1. Field
Apparatuses and methods consistent with exemplary embodiments relate to a compressor system and a method of controlling the same.
2. Description of the Related Art
In turbo compressors, when the compressors do not produce greater pressure than the pressure resistance of systems, periodic fluid backflows occur inside compressors, which are designated as surges. When the surges occur, fluids regularly flow back in such a way that minute changes in pressure and flow cause mechanical vibrations that may damage bearings and impellers. The surges as described above deteriorate the performance of compressors and reduce the lifespan thereof. Therefore, surge prevention is a significant aspect of controlling the turbo compressors.
In compressor systems of the related art, to prevent such surges, surge control lines are set up in function charts of compressors, and the compressor systems are controlled through the surge control lines. Japanese Patent Laid-open Publication No. 2007-212040, titled Turbo refrigerator and its control method, filed by MITSUBISHI HEAVY IND LTD, discloses a method of controlling a compressor system in which control is performed by setting a surge control line having a margin of about 10% from a surge line, which corresponds to a condition where a surge of a compressor occurs, set in the function chart to prevent the surge and by using an opening rate of an inlet vane and a hot gas bypass.
Also, Japanese Patent Laid-open Publication No. 2005-226561, titled Low duty compressor control method in LNG ship, filed by KAWASAKI SHIPBUILDING CORP, discloses a method of preventing a surge by setting a surge control zone, in addition to a surge control line, not to allow an operation point to be in the surge control zone.